Methods and apparatuses for executing a plurality of queued tasks in a memory

ABSTRACT

Methods and apparatuses are disclosed for executing a plurality of queued tasks in a memory. One example apparatus includes a memory configured to be coupled to a host. The memory is also configured to receive a plurality of memory access requests, a status request, and an execution command from the host, and to execute one or more of the plurality of memory access requests responsive to the execution command from the host. The execution command includes a plurality of respective indications that correspond to each respective memory access request of the plurality of memory access requests and that indicate whether the host is requesting the memory to execute each respective memory access request.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to a provisional application entitled“METHODS AND APPARATUSES FOR EXECUTING A PLURALITY OF QUEUED TASKS IN AMEMORY,” filed on Jan. 27, 2014 and assigned Application No. 61/932,155.This application is incorporated by reference herein in its entirety andfor all purposes.

BACKGROUND OF THE INVENTION

In an apparatus where data is to be transferred from a host to a memory,the data may be transferred in several different manners. In oneexample, the host may send a command to the memory (along with data tobe written to the memory in the case of a write command) and the memorymay execute the command without any further processing or otherinteraction from the host or memory. In order to accomplish this mannerof data transfer, a number of different control signals may need to beprovided from the host to the memory on dedicated signal lines—forexample, a write enable signal, a read enable signal, an address latchenable signal, a command latch enable signal, a chip enable signal, andso forth may need to be generated by the host and provided to thememory.

In other examples, the number of control signals provided from the hostto the memory (and therefore the number of signal lines between the hostand the memory) may be reduced in order to simplify the interfacebetween the host and the memory. In these examples, however, the memorymay need to do additional processing on the commands and data receivedfrom the host in order to correctly read from or write to the memory.This manner of data transfer also allows multiple memory access requeststo be sent from the host to the memory before one or more of thosememory access requests are executed. The multiple memory access requestsmay be queued until the memory is ready to execute them, and the memorymay provide ready status information to the host regarding the readinessof the memory to execute the queued memory access requests. This readystatus information may be provided to the host by continuously sendingthe ready status information to the host in some examples, but suchcontinuous transfer of ready status information (whether via continuouspolling of the memory or via a dedicated signal line that triggers aninterrupt or other action) may unnecessarily consume power and/orunnecessarily use signal lines.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an apparatus with a host that can execute aplurality of queued tasks in a memory according to an embodiment of thepresent invention.

FIG. 2A is a block diagram of a queue status register according to anembodiment of the invention.

FIG. 2B is a table of different bit values for the queue status registerof FIG. 2A and status information corresponding to those different bitvalues, according to an embodiment of the invention.

FIG. 2C is a table illustrating the structure and values for anexecution command according to an embodiment of the invention.

FIG. 3A is a timing diagram illustrating the operation of the apparatusof FIG. 1 according to an embodiment of the invention.

FIG. 3B is a timing diagram illustrating the operation of the apparatusof FIG. 1 according to an embodiment of the invention.

FIG. 4 is a block diagram of a memory array according to an embodimentof the invention.

DETAILED DESCRIPTION

Certain details are set forth below to provide a sufficientunderstanding of embodiments of the invention. However, it will be clearto one skilled in the art that embodiments of the invention may bepracticed without these particular details. Moreover, the particularembodiments of the present invention described herein are provided byway of example and should not be used to limit the scope of theinvention to these particular embodiments. In other instances,well-known circuits, control signals, timing protocols, and softwareoperations have not been shown in detail in order to avoid unnecessarilyobscuring the invention.

FIG. 1 illustrates an apparatus 100 with a host 120 coupled to a memory140, according to an embodiment of the invention. As used herein,apparatus may refer to, for example, an integrated circuit, a memorydevice, a memory system, an electronic device or system, a smart phone,a tablet, a computer, a server, etc.

The host 120 includes a host controller 124, and is configured toprovide (e.g., issue) commands to the memory 140, for example, aplurality of memory access requests. The memory access requests may berequests to read data from the memory 140, to write data into the memory140, or otherwise access and potentially manipulate the data in thememory 140. In other words, a memory access request may correspond witha data transfer being requested, and in some embodiments may includeparameters related to a direction (e.g., read, write) of the respectivedata transfer, a size of the respective data transfer, a priority of therespective data transfer, and/or an assigned request identificationnumber of the respective data transfer.

The host 120 is further configured to provide commands such as statusrequests to the memory 140 in order to request ready status informationfrom the memory 140 regarding whether the memory 140 is ready to executethe memory access requests previously provided to the memory 140. Theready status information may include an indication of whether the memoryis ready to execute one or more of the plurality of memory accessrequests and may also include an indication of when the memory 140 maybe ready to execute one or more of the plurality of memory accessrequests (if, for example, the memory 140 is not yet ready to executeone or more of the plurality of memory access requests). In someembodiments, the ready status information may indicate whether thememory 140 is ready to execute any one of the plurality of memory accessrequests, whether the memory is ready to execute multiples ones of theplurality of memory access requests, whether the memory is ready toexecute all of the plurality of memory access requests, etc.

The host 120 is also configured to provide execution commands to thememory 140, responsive to the ready status information received from thememory 140, in order to request execution of one or more of the memoryaccess requests that the memory 140 is ready to execute. In someembodiments, an execution command may be used to request the executionof a single memory access request. In other embodiments, a singleexecution command may be used to request execution of multiple ones ofthe memory access requests that the memory 140 is ready to execute. Theexecution command provided by the host 120 may include a plurality ofrespective indications that correspond to each memory access requestthat the host 120 has provided to the memory 140, each of whichindicates whether the host 120 is requesting the memory 140 to executethe respective memory access request. By allowing the host 120 toprovide a single execution command requesting execution of multiplememory access requests, fewer execution commands may be needed (therebyallowing for more efficient use of the CMD bus 132 and the DATA bus 134,which are described below).

The memory 140 includes a memory controller 142 coupled to at least onememory array 144, which may be a non-volatile (e.g., NAND flash, phasechange material, etc.) memory array 144 in some embodiments. Thecontroller 142 is configured to access the memory array 144 by executingmemory access requests received from the host 120. In one embodiment,the memory controller 142 together with the memory array 144 togetherform an embedded multimedia card (eMMC). The eMMC may also include othercomponents in some embodiments, such as additional hardware andfirmware.

The memory 140 also includes a memory access request queue 150, and aqueue status register 152 configured to indicate the status of thememory access requests in the memory access request queue 150. Thememory 140 is configured to receive the plurality of memory accessrequests, status requests, and execution commands from the host 120. Thememory 140 may also be configured to provide the ready statusinformation to the host 120, responsive to the status requests, based onwhether the memory 140 is ready to execute one or more of the pluralityof memory access requests previously received from the host 120. Thememory 140 may also be configured to provide an indication of when thememory 140 may be ready to execute one or more of the plurality ofmemory access requests in response to a status request, such as if thememory 140 is not ready to execute any of the plurality of memory accessrequests previously received from the host 120. The memory 140 may beconfigured to provide the ready status information to the host 120 byproviding the host 120 with the contents of the queue status register152.

The ready status information provided by the memory 140 to the host 120may be embedded within a larger response to the status request in someembodiments. For example, the larger response may include anacknowledgment of receipt of the status request from the host 120, errorchecking information such as a cyclic redundancy check, and so forth.

The memory access request queue 150 is configured to queue one or morememory access requests received from the host 120. In some embodiments,a plurality (e.g., two, three, ten, twenty, thirty, etc.) of memoryaccess requests may be provided from the host 120 to the memory 140before the memory 140 executes one or more of the previously receivedmemory access requests. The queue status register 152 may be configuredto maintain an indication of readiness for execution corresponding toone or more of the plurality of memory access requests received from thehost 120, for example, as described below with reference to FIG. 2B. Insome embodiments, the queue status register 152 may maintain anindication of readiness for execution corresponding to each of theplurality of memory access requests received from the host 120.

The apparatus 100 in FIG. 1 also includes a CMD bus 132, a DATA bus 134,and a CLK signal line 136 coupled between the host 120 and the memory140. In some embodiments, and with reference to FIG. 1, the CMD bus 132may be a 1-bit wide serial bus that is bidirectional (e.g., can receiveinformation from both the host 120 and the memory 140, with informationreceived from one direction propagating towards the other direction).For example, the host 120 may be configured to provide commands—such asmemory access requests, status requests, execution commands, and soforth—to the memory 140 via the CMD bus 132. Similarly, the memory 140may be configured to provide the ready status information to the host120 (responsive to the status requests from the host 120) via the CMDbus 132.

The DATA bus 134 may be several bits (e.g., 8 bits) wide in someembodiments, and may also be bidirectional. The host 120 may beconfigured to provide data (e.g., write data to be written to the memory140) to the memory 140 via the DATA bus 134, and the memory 140 may beconfigured to provide data (e.g., read data that is read from the memory140) to the host 120 via the DATA bus 134.

The CLK signal line 136 provides a reference clock from the host 120 tothe memory 140, which may be used as a strobe signal to clock commandsand/or data provided between the host 120 and the memory 140 on the CMDbus 132 and the DATA bus 134.

In some embodiments, the ready status information provided to the host120 includes an indication of whether the memory 140 is ready to executememory access requests received from the host 120 and queued in thememory access request queue 150. In some embodiments, the ready statusinformation may be based on whether the DATA bus 134 is available fordata transmission between the host 120 and the memory 140. In someembodiments, the ready status information provided to the host 120 mayonly be valid for a duration of time after it is provided by the memory140, and/or may only be valid if there are no intervening commands orrequests made of the memory 140. For example, ready status informationindicating that a memory access request or several memory accessrequests are ready for execution may only be valid for 100 milliseconds,and may further become invalid if the host 120 provides an additionalmemory access request to the memory 140 that, for example, has a higherpriority than the memory access requests currently pending in the memoryaccess request queue 150.

Referring still to FIG. 1, in operation, the host 120 provides aplurality of memory access requests to the memory 140 by, for example,providing the memory access requests to the CMD bus 132. The memory 140in turn receives the plurality of memory access requests from the host120 via the CMD bus 132. In some embodiments, the host 120 may assign arequest identification number to one or more of the plurality of memoryaccess requests before providing the memory access requests to thememory 140. In other embodiments, however, the host 120 may providememory access requests to the memory 140 without referenceidentification numbers, and the memory 140 may assign requestidentification numbers to the received memory access requests.

After the memory 140 receives one or more memory access requests fromthe host, the memory may prepare itself to execute the one or morememory access requests. The memory may prepare itself, for example, byinspecting the memory access requests already in the memory accessrequest queue 150, performing error handling operations related toreceived memory access requests, ordering the memory access requests inorder to improve performance of the memory during execution of thoserequests or in order to conform to priorities assigned to the requestsby the host 120, updating the memory access request queue 150 and thequeue status register 152 based on the newly received memory accessrequest, and so forth.

After providing one or more memory access requests, the host 120 mayprovide a status request in order to request ready status informationfrom the memory 140. In response to the status request from the host120, the memory 140 provides the ready status information to the host120 via the CMD bus 132. The ready status information may be indicativeof whether the memory is ready to execute one or more of the pluralityof memory access requests, and in some embodiments may include anestimated relative wait time before the memory may be ready to executeone or more of the plurality of memory access requests (e.g., if thememory is not yet ready to execute any of the plurality of memory accessrequests).

In some embodiments, separate ready status information (or separateindications within a single ready status information) may be providedfor respective ones of a plurality of memory access requests provided tothe memory 140. For example, for respective ones of the plurality ofmemory access requests, the ready status information may include anindication of whether the memory 140 is ready to execute that specificmemory access request and/or an indication of when the memory may beable to execute that specific memory access request, with indications ofwhether the memory 140 is ready to execute another specific memoryaccess request and when the memory may be able to execute that otherspecific memory access request being provided in separate ready statusinformation, or provided in separate parts of a single ready statusinformation. In some examples, separate indications may be provided foreach respective memory status request, whereas in other embodimentsseparate indications may be provided only for different types of memoryaccess requests (e.g., one indication for all reads, one indication forall writes, etc.), and in still other embodiments, one type ofindication (e.g. whether the memory is ready) may be provided for eachrespective memory access request and one type of indication (e.g., whenthe memory will be ready to execute one or more memory access requests)is provided for the memory access requests collectively.

The host 120, after receiving ready status information from the memory140 indicating that one or more requests are ready for execution, mayprovide an execution command to the memory responsive to that readystatus information. The execution command may correspond to one or moreof the memory access requests received from the host 120—for example, ifthe ready status information indicates that the memory access requestthat has been assigned request identification number 1 is ready to beexecuted by the memory 140, the host may request execution of thatmemory access request.

As mentioned above, in those embodiments where the execution commandcomprises a plurality of indications indicating whether the host isthereby requesting execution of each respective one of a plurality ofdifferent memory access requests, a single execution command may be usedto request execution of multiple ones of the memory access requests. Themultiple ones of the memory access requests that the host 120 requeststo be executed may include some but not all of the memory accessrequests provided to the memory 140 in some embodiments. Further, insome embodiments, the execution command may be limited to a specifictype of memory access (e.g., read or write), and the grouping ofmultiple memory access requests into a single execution command may belimited by the type of memory access. In other words, in someembodiments, only similar types of memory access requests (e.g., read orwrite) can be grouped together in a single execution command.

In some embodiments, when the execution of more than one memory accessrequests are included within a single execution command, the memory 140may be configured to execute the multiple memory access requests innumerical order according to the respective request identificationnumbers assigned to the memory access requests. For example, if anexecution command includes indications indicating that memory accessrequests 2, 4, 8, and 10 should be executed, the memory 140 may executememory access request 2 first, memory access request 4 second, memoryaccess request 8 third, and memory access request 10 last. Of course, inother embodiments, the memory 140 may be configured to execute thememory access requests in reverse numerical order.

In still other embodiments, the memory 140 may be configured todetermine a suggested execution order for the memory access requests andprovide the same to the host 120. The memory 140 may, for example,provide the suggested execution order to the host 120 together with theready status information in response to receiving a status request fromthe host. In response to receiving the suggested execution order, thehost 120 may be configured to provide an indication of whether thememory 140 should use the suggested execution order in executing therequested memory access requests.

In still other embodiments, the memory 140 may be configured to providean actual execution order to the host 120, with the actual executionorder indicating the order in which the memory will execute each of theplurality of memory access requests that the host 120 has requested beexecuted. In other words, the actual execution order may not just be‘suggested,’ but may be the actual order in which the memory 140 willexecute the memory access requests. The memory 140 may send thisinformation to the host 120 so that the host can properly coordinatedata being read from or written to the memory 140 with the queued memoryaccess requests, in case the memory access requests are not executed in,for example, numerical order. In some embodiments, the memory 140 maysend the actual execution order to the host 120 as part of anacknowledgment response to an execution command, or alternatively, thememory may send the actual execution order to the host 120 as part of aresponse to receiving a status request from the host 120.

In those embodiments where the memory 140 determines a suggested oractual execution order, the order may be based on the ability of thememory 140 to more quickly execute certain commands in a certain order.If, for example, the plurality of memory access requests are allread-type requests, and the addresses corresponding to two of the memoryread access requests are close together, the memory 140 may be able toexecute those two memory read access requests more quickly if doneback-to-back, as opposed to having intervening memory read accessrequests with other addresses. Thus, allowing the memory 140 to suggestor set forth an execution order may result in improved performance ofthe apparatus 100.

In still other embodiments, the host 120 may be configured to determinea suggested execution order and to provide the suggested execution orderto the memory 140. In these embodiments, the memory 140 may beconfigured to provide a response to the host indicating whether thesuggested execution order will be used—which may for example be providedin an acknowledgment response to an execution command and/or to a statusrequest. In still other embodiments, the host 120 may be configured todetermine an actual execution order and to provide the same to thememory 140. In some embodiments, the host 120 may determine thesuggested or actual execution order based on its understanding of theinternal structure of the memory 140 and the addresses of the memoryaccess requests that it has provided to the memory.

FIG. 2A illustrates an embodiment of the queue status register 152according to an embodiment of the invention. As illustrated in FIG. 2A,the queue status register 152 includes a collection of registers 155configured to store indications of readiness corresponding to aplurality of memory access requests received by the memory 140. In someembodiments, the collection of registers 155 may be mapped one-to-one topending memory access requests, with the bit position i in the queuestatus register 152 corresponding to a request identification numberassigned to the respective request. The collections of registers 155defines at least in part the queue status register 152, and holds readystatus information relating to a plurality of memory access requestsreceived by the memory 140.

FIG. 2B illustrates values that the bits in the first collection ofregisters 155 may take during operation of the queue status register152. For example, the bit in the 0^(th) position of the queue statusregister 152 may store an indication that the memory access request thathas been assigned a request identification number of 0 is or is notready for execution. When the bit in the 0^(th) position is a logic low(e.g., 0), this may correspond to the 0^(th) memory access request notbeing ready for execution, whereas when the bit in the 0^(th) positionis a logic high (e.g., 1), this may correspond to the 0^(th) memoryaccess request being ready for execution. In this manner, the firstcollection of registers 155 in the queue status register 152 indicatewhich of the memory access requests received by the memory 140 are readyfor execution.

FIG. 2C illustrates the structure and values of an execution commandthat may be provided from the host 120 to the memory 140. The executioncommand structure illustrated in FIG. 2C includes 48 bits, with a headerin the most significant 8 bits, an argument containing theidentification numbers of the memory access requests that the host 120wants the memory 140 to execute in the middle, and a footer in the leastsignificant 8 bits. The header and footer may include, for example,error correction information, a command type (e.g., read or write),starting and ending transmission bits, and so forth.

As illustrated in FIG. 2C, the argument of the execution commandcorresponding to the memory access requests that the host 120 wants thememory 140 to execute may be in a bitmap format, with each respectivebit corresponding to a respective one of the plurality of memory accessrequests. For example, the bit in the least significant bit position ofthe argument (e.g., bit 8 in FIG. 2C) may correspond to a memory accessrequest which has been assigned an identification number of 0, the bitin the next to least significant bit position (e.g., bit 9 in FIG. 2C)may correspond to a memory access request which has been assigned anidentification number of 1, and so on. The value of each bit in theargument may correspond to whether or not the corresponding memoryaccess request should be executed. For example, a logic high value(e.g., 1) may correspond to a request from the host 120 to execute thecorresponding memory access request, while a logic low value (e.g., 0)may correspond to the host 120 not requesting the execution of thecorresponding memory access request.

With reference still to FIG. 2C, the structure of the execution commandmay be such that the host 120 can request that one or multiple ones ofmemory access requests be executed by the memory 140. In other words,given the example above, if just one of the bits of the argument is setto a logic high value, the execution command corresponds to a request bythe host 120 for the memory 140 to execute a single memory accessrequest. If, on the other hand, multiple bits in the argument of theexecution command are set to logic high values, then the executioncommand may correspond to a request by the host to execute multiplememory access requests without an intervening execution command.

Referring now to FIG. 3A, one example of operation of the host 120 andmemory 140 of FIG. 1, and the queue status register 152 of FIGS. 1 and2A will be described. At time T1, the host 120 provides a status requestto the memory 140 via the CMD bus 132 in order to request ready statusinformation from the memory 140. At time T2, the memory responds to thestatus request by acknowledging receipt of the status request andproviding the contents of the queue status register 150 to the host viathe CMD bus 132. In this instance, because no memory access requestshave been received by the memory 140, the response provided by thememory 140 is that no requests are ready for execution.

At time T3, the host 120 provides a first memory access request to thememory 140 via the CMD bus 132. The memory 140 responds at time T4 withan acknowledgment of receipt of the first access request. Upon receiptof the first memory access request, the memory controller 142 mayinitialize the indication of whether the memory 140 is ready to executethe first memory access request to “not ready for execution” by settingthe corresponding bit in the queue status register 152 to a logic low.Further, the memory 140 may begin preparing itself to execute the firstmemory access request after receiving it so that it can change theindication of whether it is ready to execute the first memory accessrequest after the preparations are complete.

Although FIG. 3A illustrates the first memory access request beingprovided by the host 120 as a single command, and a single responsebeing provided by the memory 140, in some embodiments, memory accessrequests may be split into two different commands, which may cause thememory 140 to respond separately with two separate responses.

At time T5, the host 120 provides a second memory access request to thememory 140 via the CMD bus 132, and the memory 140 responds at time T6with an acknowledgment of receipt of the second access request. At timeT6, the memory has received a plurality of memory access requests, noneof which have been executed yet. In some embodiments, when the memory140 receives a new memory access request from the host 120, the memory140 may reconsider the requests it has previously indicated as beingready or not ready for execution based on the priorities of the newlyreceived memory access request and the previously received memory accessrequests. For example, if the newly received memory access request has ahigh priority whereas the previously received and still unexecutedmemory access requests in the memory access request queue have lowpriorities, the memory 140 may revoke the readiness to execute thoselower priority requests in order to prepare the memory 140 to executethe newly received high priority memory access request. In general, thememory access requests may, in some embodiments, become ready forexecution based on respective priorities assigned by the host 120 torespective ones of the plurality of memory access requests.

At times T7, T9, T11, T13, T15, T17, T19, and T21, the host 120 providesadditional memory access requests (memory access requests #3, #4, #5,#6, #7, #8, #9, and #10) to the memory 140, and the memory responds attimes T8, T10, T12, T14, T16, T18, T20, and T22 with respectiveacknowledgment responses. At time T23, the host 120 provides a statusrequest to the memory 140, and the memory 140 responds at time T24 byproviding the contents of the queue status register 150 to the host 120via the CMD bus 132. As illustrated in FIG. 3A, the contents of thequeue status register 150 provided to the CMD bus 132 at time T24indicate that the memory is ready to execute memory access requests #2,#4, #8, and #10. At this point, the host 120 may decide to execute oneor multiple ones of memory access requests #2, #4, #8, and #10.

If the host 120 decides to execute all of the memory access requeststhat are ready for execution, the host 120, at time T25, may provide anexecution command to the memory 140 with indications indicating that thememory should execute memory access requests #2, #4, #8, and #10. Thememory 140 responds at time T26 with an acknowledgment that theexecution response was safely received and that it will soon beginexecuting memory access requests #2, #4, #8, and #10. Then, at timesT27, T28, T29, and T30, the memory 140 executes the memory accessrequests #2, #4, #8, and #10 by providing read data to the DATA bus 134,which is received at the host 120. The read data provided by the memoryat times T27, T28, T29, and T30 is provided back-to-back and withoutinterruption—e.g., without any intervening execution commands.

As described above, the memory 140 may execute memory access requests#2, #4, #8, and #10 in some particular order. The order in which thememory access requests #2, #4, #8, and #10 are executed may be based onthe identification numbers (e.g., numerical execution), or may bedetermined by the host 120 and/or the memory 140. The execution commandprovided at time T25, and/or either of the memory responses provided attimes T24 or T26 may include order information—such as a suggested oractual order in which the memory 140 should or will execute theplurality of memory access requests identified in the execution command.

After time T30, the host 120 may request additional status informationfrom the memory 140, and if the memory 140 is ready to executeadditional memory access requests, the host 120 may provide anotherexecution command to the memory 140

FIG. 3B illustrates another example of operation of the host 120 andmemory 140 of the apparatus 100 of FIG. 1. The operation illustrated inFIG. 3B is similar to the operation illustrated in FIG. 3A, except thatduring execution of one of the memory access requests, an executionerror occurs (at time T28). In some embodiments, and as illustrated inFIG. 3B, the memory 140 may stop execution of the plurality of memoryaccess requests once an execution error occurs. In other embodiments,the memory 140 may continue to execute any remaining memory accessrequests.

The memory 140 may in some embodiments provide an indication to the host120 that an execution error occurred. For example, in response to astatus request provided to the memory 140 at time T29, the memory 140may respond with an indication of the execution error. In otherembodiments, the memory 140 may send the execution error notification tothe host 120 via an interrupt or other communication.

The host 120 may in some embodiments request additional information fromthe memory 140 regarding the execution error. For example, the host 120may need to know which of multiple ones of memory access requests causedthe execution error. In order to obtain this additional information, thehost 120 may request an error report from the memory 140, and the memory140 may respond to the request with the error report. In some examples,the request for the error report may be sent as part of a statusrequest—and the error report may be returned in a format similar to theready status information provided by the queue status register152—specifically, a bitmap may be provided with each bit indicatingwhich of the memory access requests caused the execution error.

FIG. 4 illustrates a memory array 400 according to an embodiment of theinvention. The memory array 400 may be used as the memory array 144 inthe apparatus 100 of FIG. 1 in some examples, and includes a pluralityof memory cells 430. The memory cells 430 may be non-volatile memorycells, such as NAND or NOR flash cells, phase change memory cells, ormay generally be any type of memory cells.

Command signals, address signals and write data signals may be providedto the memory 400 as sets of sequential input/output (“I/O”) signalstransmitted through an I/O bus 428. Similarly, read data signals may beprovided from the memory 400 through the I/O bus 428. The I/O bus 428 isconnected to an I/O control unit 420 that routes the signals between theI/O bus 428 and an internal data bus 422, an internal address bus 424,and an internal command bus 426. The memory 400 also includes a controllogic unit 410 that receives a number of control signals eitherexternally or through the command bus 426 to control the operation ofthe memory 400, and which may generally correspond to the memorycontroller 142 of the apparatus 100 illustrated in FIG. 1.

The address bus 424 applies block-row address signals to a row decoder440 and column address signals to a column decoder 450. The row decoder440 and column decoder 450 may be used to select blocks of memory ormemory cells for memory operations, for example, read, program, anderase operations. The row decoder 440 and/or the column decoder 450 mayinclude one or more signal line drivers configured to provide a biasingsignal to one or more of the signal lines in the memory array 430. Thecolumn decoder 450 may enable write data signals to be applied tocolumns of memory corresponding to the column address signals and allowread data signals to be coupled from columns corresponding to the columnaddress signals.

In response to the memory commands decoded by the control logic unit410, the memory cells in the array 430 are read, programmed, or erased.Read, program, and erase circuits 468 coupled to the memory array 430receive control signals from the control logic unit 410 and includevoltage generators for generating various pumped voltages for read,program and erase operations.

After the row address signals have been applied to the address bus 424,the I/O control unit 420 routes write data signals to a cache register470. The write data signals are stored in the cache register 470 insuccessive sets each having a size corresponding to the width of the I/Obus 428. The cache register 470 sequentially stores the sets of writedata signals for an entire row or page of memory cells in the array 430.All of the stored write data signals are then used to program a row orpage of memory cells in the array 430 selected by the block-row addresscoupled through the address bus 424. In a similar manner, during a readoperation, data signals from a row or block of memory cells selected bythe block-row address coupled through the address bus 424 are stored ina data register 480. Sets of data signals corresponding in size to thewidth of the I/O bus 428 are then sequentially transferred through theI/O control unit 420 from the data register 480 to the I/O bus 428.

From the foregoing it will be appreciated that, although specificembodiments of the invention have been described herein for purposes ofillustration, various modifications may be made without deviating fromthe spirit and scope of the invention. For example, FIG. 1 illustratesembodiment of a host 120, a host controller 124, a memory 140, a memorycontroller 142, a memory array 144, a memory access request queue 150, aqueue status register 152, and so forth, FIG. 2A illustrates anembodiment of a queue status register 152, and FIG. 4 illustrates anembodiment of a memory array 400. However, other hosts, hostcontrollers, memories, memory controllers, memory arrays, memory accessrequest queues, queue status registers, and so forth may be used, whichare not limited to having the same design, and may be of differentdesigns and include circuitry different from the circuitry in theembodiments illustrated in the figures.

Accordingly, the invention is not limited to the specific embodiments ofthe invention described herein.

What is claimed is:
 1. An apparatus, comprising: a memory configured toreceive from a host a plurality of memory access requests, a statusrequest, and an execution command, and further configured to queue theplurality of memory access requests in a request queue and to executeone or more of the plurality of memory access requests responsive to theexecution command from the host; wherein the execution command comprisesa plurality of indications, each of the plurality of indicationscorresponding to a respective one of the plurality of memory accessrequests queued in the request queue, and indicating whether the host isrequesting the memory to execute the respective one of the plurality ofmemory access requests.
 2. The apparatus of claim 1, wherein each of theplurality of memory access requests is assigned a respective requestidentification number and, in the event that the execution commandindicates that the host is requesting execution of more than one of theplurality of memory access requests, the memory is configured to executethe more than one of the plurality of memory access requests innumerical order according to the respective request identificationnumbers.
 3. The apparatus of claim 1, wherein the memory is configuredto determine a suggested execution order and to provide the suggestedexecution order to the host.
 4. The apparatus of claim 3, wherein thememory is configured to provide the suggested execution order to thehost together with ready status information in response to the statusrequest.
 5. The apparatus of claim 3, wherein the execution commandreceived from the host further comprises an indication of whether thememory should use the suggested execution order.
 6. The apparatus ofclaim 1, wherein the memory is configured to provide an actual executionorder to the host in response to the status request, the actualexecution order indicating the order in which the memory will executeeach of the plurality of memory access requests that the host hasrequested be executed.
 7. The apparatus of claim 6, wherein the memoryis configured to provide the actual execution order to the host togetherwith ready status information in response to the status request.
 8. Theapparatus of claim 1, wherein the memory is further configured toprovide an error report to the host responsive to receiving a requestfor the error report after the occurrence of an execution error.
 9. Anapparatus, comprising: a host configured to provide a plurality ofmemory access requests, a status request, and an execution command to amemory, and to receive ready status information from the memoryresponsive to the status request, wherein the plurality of memory accessrequests to be queued in a request queue of the memory; wherein the hostis further configured to provide the execution command responsive to theready status information, and the execution command comprises aplurality of indications, each of the plurality of indicationscorresponding to a respective one of the plurality of memory accessrequests queued in the request queue and indicating whether the host isthereby requesting execution of the respective one of the plurality ofmemory access requests.
 10. The apparatus of claim 9, wherein theexecution command is structured such that the host can request that oneor multiple ones of the plurality of memory access requests be executedby the memory via the execution command.
 11. The apparatus of claim 9,wherein a logic high value for one of the plurality of indications ofthe execution command corresponds to a request from the host to executethe respective memory access request.
 12. The apparatus of claim 9,wherein the host is further configured to determine a suggestedexecution order and to provide the suggested execution order to thememory.
 13. The apparatus of claim 12, wherein the host is configured toreceive a response from the memory indicating whether the suggestedexecution order will be used.
 14. The apparatus of claim 9, wherein thehost is further configured to determine an actual execution order and toprovide the actual execution order to the memory.
 15. The apparatus ofclaim 9, wherein the host is further configured to request an errorreport from the memory responsive to receiving an indication from thememory that an execution error occurred.
 16. A method, comprising:providing a plurality of memory access requests to a memory to be queuedin a request queue of the memory; requesting ready status informationfrom the memory indicative of whether the memory is ready to executefirst and second memory access requests of the plurality of memoryaccess requests queued in the request queue; and providing an executioncommand to the memory responsive to the ready status informationindicating that both the first and second memory access requests of theplurality of memory access requests queued in the request queue areready for execution, the execution command comprising first and secondindications requesting execution of the first and second memory accessrequests of the plurality of memory access requests queued in therequest queue, respectively.
 17. The method of claim 16, wherein thefirst and second indications requesting execution of the first andsecond memory access requests are included within a single executioncommand.
 18. The method of claim 16, wherein at least one argument ofthe execution command is provided in a bitmap format, with eachrespective bit of the at least one argument corresponding to arespective one of the plurality of memory access requests.
 19. Themethod of claim 16, further comprising requesting an error reportresponsive to receiving an indication from the memory that an executionerror occurred.